Leg2ion

'How does a collective work' - such an innocent question and bound to elicit a few multi faceted responses! So, (and as eluded to in a few responses to above) a Collective control is a pilot input lever that will 'collectively' increase/decrease pitch on all blades at the same time. Unfortunately - things are not that simplistic, so whilst the desire may be to increase pitch (initially) uniformly across all blades - this cannot happen due to advancing and retreating blade speeds coupled with aircraft forward speed. In essence - in forward flight advancing blades - so those going forward into the airflow - need less pitch (which equates to less lift) due to increased airflow (advancing speed plus fwd aircraft speed) across the aerofoil section of the blade, whilst those retreating - so heading backwards away from fwd speed airflow need more pitch (equating to more lift) due to decreased airflow (retreating blade speed minus fwd aircraft speed). Overall effect is to keep relative lift across the rotor disc equal to prevent dissymmetry of lift. This is governed by basic flight control rigging where everything is pinned in position and angles set by adjusting the control rods (simplistic explanation)! In terms of 'power' - in the good ole days a lot of levers had a twist grip throttle, so was down to pilot skill to 'roll on' power to the engines to sustain power to maintain rotor speed - so the engines were manually governed. If you can picture a case whereby the blade pitch increases when the collective was raised to, say, transition into a hover from initial start-up, so in terms of airflow across the disc the blades will slow down, so the engines need to provide more power to maintain or increase rotor speed to counter the slow down effect. Then things got a little bit more advanced, whereby the throttle (independent of the collective) would be set (to fly), and the engines were fitted with a governor which would detect engine slow down (which meant rotor slow down) so would open a valve in the fuel management unit to increase fuel flow to increase speed and counter the slow down. Minor pilot input was required. Nowadays there are electronic control units fitted, and the system is basically automated - the idea being to take the workload off the pilot (who has better things to be doing on a battlefield). So these units govern the engine power output into the rotors transmission to maintain rotor speed - and are fed by a myriad of variables (from the airframe sensors and the engines), and in addition have 'anticipators' - another unit that will detect collective movement and anticipate a power demand (or reduction) and tailor the fuel flow to suit. Then you need to factor in the yaw and cyclic inputs and how the interlinks interact ...

Hi @Caldera . I think you may be getting some of your terminology mixed. When a 'hot start' is referred to it means just that - in that the temperatures that are monitored - normally at the turbine end of the engine - are too hot and have been exceeded on start up - hot start. Normally occurs when the engine power lever is advanced too quickly or too much load/power is demanded at start up before the engine is working correctly, and caused by insufficient airflow through the engine before a large amount of fuel is dumped into the combustor can. Once the engine is up and running properly bleed air is used to maintain/shape the flame in the combustor can to provide clean gas flow into the turbines to drive them, and then also provide cooling air across the turbine discs. IRL a hot start can result in something simple as a few boroscope inspections in the can and on the discs, or dependent on temperature reached engine rejection. As to your questions: Oil pumps - engine driven. Overall fairly low pressure so a quick rise is to be expected. In older aircraft types you would expect to see the pressure rise higher than normal (into the yellow) then as the pressure relief valve in the system kicks in start self regulating and come back down to the green. In terms of mimicking the rotor speed rise - assume you are monitoring No2 engine - so there is a direct relation between engine acceleration/speed (and subsequent drive to the engine mounted oil pump) and Nr. Rotor rotation - shouldn't be able to be used to restart an engine as the freewheels should decouple the rotors (spinning faster) from the engines (spinning slower). Normally either an APU is used to go through a 'standard' engine start or there is an ability to use bleed air off the one good engine if there is one. Purging - also called venting. If you have had a real hot start (but within limits allowing normal ops to continue) or aborted start for whatever reason then (dependent on engine manufacturer requirements) a shut down is required, sometimes a cooling off period of time, and sometimes a purge - so run/vent the engines for 30 seconds with fuel/ignition turned off as an example. Looking at some of the other questions/comments I believe that both the GE T700 (US) and the RR RTM322 (UK) are spun up with a pneumatic air starter powered by bleed air off the APU.

I fly with custom curves - shown at this link - I did feel them to help. Initially I found that the slightest yaw input would give me a spin, so after some guidance from elsewhere in the forum flattened the yaw/pitch/roll out around the centre point. Hope that helps - though really think a lot depends on your setup/feel and what works for you...

Glad to be of help. I do occasionally have a play with them - but normally end up back from where I started.

Currently using TM T.Flight pedals - which seem adequate. I find if I apply pedal then just as the nose starts to yaw I ease up a slight bit it is controllable. If I get 'hard' yaws make an input and let it settle - takes some nerve at first to avoid chasing the movement.....

Hi @JOEM423... In order to get back to your request (as opposed to a discussion whether curves are good/bad, unrealistic if you wish to fly a real AH (trying to ignore the statement about making your life easier - it is a game after all!) etc...see below. They are what I use, with a standard TM HOTAS setup - with the stick/cyclic set to the right of my chair. I found someone elses custom curves elsewhere in the forums - which I used as a starting point - so you should do the same - and tweak them until you feel right. The idea behind my curves is a 'soft cushion' around the centre point but then emulates linearity as you go outside this. In addition I also have a slight curve on my collective - to try to reduce the 'Rotors' warning when I pull pole at hot/high locations (initially set up a training flight in Nevada - then transferred it to Caucasus - makes a helluva difference). Without curves I found that what felt right in one situation didn't work in another, and the below certainly helped... Yaw: Pitch/Roll:

Don't be. I had similar misgivings, and initially set up flight control and trim mapping only (ignoring all things weapons/sights), then created a hot start free flight mission just to get a feel of things. Still practicing starts, take off, circuits and landings, with the occasional training mission thrown in to start mapping weapons controls in the front seat.

Likewise here...intended for low speed/local air data for feed into Fire Control System. Correct term is HADS probe.

Well that is odd, as the gun didn't function from the CPG seat until I raised the trigger guard. Will refly the mission and check - but had the same problem a few times whereby the gun wouldn't fire from CPG station - and cannot think why I would have been trying to fire from the pilots pos - as the initial steps of the training mission are all CPG. Definitely had a screen with handgrips either side staring at me.

@dburne think you may be in the same boat as me. All lined up - target visually acquired, lased, lased and lased again. Switched to guns....annnnnd...nothing. Went round the buoy a few times on this. DO NOT FORGET to map the trigger guard open/close function and then open it - otherwise nothing happens...

W, S, A, D - A and D - if pushed and held will move the heading pointer around the compass. W and S - if pressed briefly will increase/decrease speed - is pressed and held will adjust the height. I think! Just done the gun training missions and by the time I had figured out how to send commands to George couldn't figure out how to get the gun online!

Currently using TM Flight Pedals - which seem OK once use to them and tuned correctly. Have set them up with custom curves, and to be honest they perform fine - albeit still learning to fly the AH - but getting easier by the hour... Think everyone is forgetting the AH is old technology - first flown in mid 70's so the DCS model is 30 years in the making. Up close and personal the flying controls are pretty agricultural, and quite heavy - so when people are comparing them with something like a Gazelle - there is no comparison as such.

Same boat! Still getting to grips with basic manoeuvres - lots of rolling take off, banking turns and an attempt to land at a place of my choosing - not where the aircraft takes me - normally resulting in No1 Eng destruction. For now going with leaving it off, then after a flight turning it on to see where all my various trimming inputs have 'centred' the controls. Normally find the pedals are slightly left pedal forward and the cyclic about a third of the way fwd pitch close to centre.

Likewise. I had it printed by an online printer service. Tad pricey but worth it. Used craftcloud - that give you loads of options (too many if a novice in my view) - with good customer support. First print arrived warped so a new one was printed and dispatched at no extra cost.

Hi @Pepsi Link for the .STL files here (another post where someone else asked for them). A word of caution - I had mine printed out remotely - and the left edge kept distorting/warping - although once on the screen and the MFD screwed on flattened out nicely. One solution may be to increase the thickness to 3mm from 2mm.

I believe it was posted in AH (with a reference to A10), having searched for any similar issues, but thanks.

Obviously! Mebbe you could request 'Multi-display Helios Touch Only (cos nothing else counts)'...

See attached. Mission hot start. Engines shut down. APU off. Battery off... MFD Remaining On.trk

When you say MFDs do you mean the ones on your main screen or exported to a 2nd monitor? I had a similar issue in that my export MFDs stay blank after start up - until I jumped into the CPG position and back again. After shutdown try doing just that and see what happens. Out of curiosity how have you exported them. I have the CPG MPDs displayed on a 2nd monitor but have no control - them freezing on the image at the point I leave the CPG station.

Yup - agree. Only things that may effect wear would be possible 'chattering' due to lack of load - but minimal in terms of wear. However - if you look at the AH start as soon as you accelerate No1 to GI it starts turning the rotor - indicating more load - though I would believe that load/wear would be more borne by the MGB input drives and not the engines.

Hi @Toni Carrera - been playing with AH over the last few days - and can only but empathise! What seems good in one situation goes completely wrong in another. I ended up setting up custom curves (reference here) - and not generic - which give me a 'softer' central control position for yaw/pitch/roll - but also give me a linear input above a certain value. These have definitely improved my general handling.... Would also suggest setting up a local mission to play with 'on finals' landings - to get use to the sensitivity/reactivity of the collective for landing practice. When I initially started I set up a mission at High Altitude in the test range - oh how so twitchy. I then set up another mission in Caucasus - completely different handling characteristics...

Good question. Personally always go with the start order of No1 then No2. Normally you will find that an engine manufacturer caters for most scenarios, and doesn't care about starting order, as it would have been designed to cope with a start under load (direct drive to the transmission) if say on a single engined aircraft. Alternating starts may effect engine life cycles, which in turn will effect maintenance and overhaul - potentially leading to No1 Eng undergoing maintenance more often if No1 is always started first - albeit dependent on how long it is between No1 and No2 starting... . The alternating method may have been a 'local order' from the maintenance section to help alleviate supply and stores issues to try to align running hours. It also does depend on how the user records usage - whether operating hours, airborne hours, hours above a certain % Ng or Np...the variables are endless and quite often co-dependent on the end user. In the case of the British Army - up until the AH appeared the helo of choice was a Lynx - with the ability to run No1 engine in an accessory drive mode, so whilst burning and turning was not providing any drive to the main transmission - but all the while was running up operating hours resulting in maintenance if the metric was op hours and not flight (under load) hours. Apologies but you did ask!

Must've missed that post!? Regarding this - I have found there does appear to be some differences. Very new to this module, and up until now have been doing hot starts (everything already online) just to practice take-offs/landings and to start mapping my controls/setting axis curves etc. Now I think I have my curves set (many thanks to @mwlueposting his custom curves here - slightly tweaked to suit my setup) I have looked into basic start up training mission. Once I have gone through a start the aircraft does seem slightly more 'twitchy' compared with starting a training mission already up and running - and in particular the yaw - to the point I had to go back into options to check they were still being applied, and then into the MPDs to make sure SCAS was selected. Maybe its me - having noticed this at the end of a 2 hour session - but did seem more 'lively'.

@JIMJAM - well said. This module does take practice (only had it 3 days) but enjoying the steep learning curve - deffo out of my comfort zone from loitering around a FEBA in an A10...

So - finally got around to downloading the AH module, jumped into the seat - and (I think) veered violently to the left then rolled. So - what did I do wrong...maybe lack of respect expecting to graduate through flight school in around 5 minutes!? Went again, and again, and again...different issues though same sort of result - major work for the maintenance teams! Bit of research - happened upon this thread (I was trying to fly 'raw') and have now messed with trim and curves. My issue now is I cannot settle on any particular curve values. Initially set all three axis at 8, then after some trial and error bumped them up to 35, back to 25, then to 15, then back to 25....basically what seems good in one scenario may not be too good for another. Looking at all 'the discussion/arguments' on trim reset in my mind live and let live - if you don't like it don't use it. The main issues appear to be around landing, take-off and hover. I now have around 3 hours flight time (1 death) and only really tend to use trim once airborne to establish S+L flight. Take-off not too bad but landing (hover is another matter completely that I need to master) is too 'needy' to be able to keep trimming - once on a slowing descent towards the tarmac I tend to trim once and then 'handle it' - only again using trim once safely back on the ground. Unfortunately I don't think any level of trim will equate to stability - which I believe the majority are looking for from the get go. The AH is a wiley beast - and does need a fair degree of respect until its nuances are mastered. If anyone has a quick fix to leap into a 20ft hover, maintaining a 0 drift please let me know. After my aforementioned 3 hours I can now take off (tarmac rolling - a hover then transition is more luck) and for the most part land - and in a breakthrough last night - where I actually intend on landing and not close by!